Hoists may be used to apply pulling force through a cable or other lifting medium to a load. Hoists and hooks are used in various vertical applications including, for example, cranes and aircraft mounted rescue hoists. Hoists may typically have a hook at the end of a cable that is attachable to the load. During operation, a hook may be lowered and directed to a target to retrieve an item or may be lowered toward a target and released to emplace a load at a target location. Moving the hook to a target may involve manual processes such as a pilot moving the helicopter from which the hoist is being operated.
Rescue conditions and other hoist operation at sea may include tidal variations and uneven sea levels associated with waves. A target in such an operation may be moving in a complex fashion in response to the undulating sea surface.
Furthermore, the hook at the end of a cable may move with a delay relative to the motion of the hoist at the top of the cable or the structure to which the hoist is attached. Thus, a pilot may move a helicopter, for example, in an attempt to deliver the hook to a target only for the target to shift before the hook is positioned.